Field of the Invention
The present invention relates to a semiconductor device which has a wide gap semiconductor element and which is capable of detecting a temperature of the wide gap semiconductor element.
Description of the Background Art
Conventionally, for measuring an operating temperature of a power semiconductor element, there has been generally used a semiconductor device having a power semiconductor element. The semiconductor device has a temperature detecting element such as a polysilicon diode formed therein electrically independently from the power semiconductor element to detect temperature of the power semiconductor element by temperature characteristics of the temperature detecting element. As a semiconductor device of this type, there is, for example, a current conversion device disclosed in Japanese Patent Application Laid-Open No. 2006-271098.
In a conventional semiconductor device which has a temperature detecting function of a power semiconductor element and is integrated into one chip, as described above, a temperature detecting element is formed inside the semiconductor device together with a power semiconductor element to detect an operating temperature of the power semiconductor element by using temperature characteristics of the temperature detecting element. Consequently, there have been disadvantages in forming a pad portion for transmitting and receiving a signal between the temperature detecting element and the outside. This configuration increases a device (chip) area to lead to cost increase, and requires an excessive wire bonding process in the pad portion to impose a greater constraint on assembling of the semiconductor device.
In addition, in a case of a wide gap semiconductor element in which a power semiconductor element is formed of a wide gap semiconductor material having light-emitting property, there has been a problem in that when the wide gap semiconductor element is operated at a high temperature of 200° C. or higher intended during the operation thereof, the conventionally used temperature detecting element such as a photodiode does not operate and is unusable.